v3.19.2
DEI Document - shares
6 Months Ended
Jun. 30, 2019
Jul. 31, 2019
Document Information [Line Items]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2019  
Document Transition Report false  
Entity File Number 1-16417  
Entity Registrant Name NuStar Energy L.P.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 74-2956831  
Entity Address, Street 19003 IH-10 West  
Entity Address, City San Antonio  
Entity Address, State TX  
Entity Address, Zip Code 78257  
City Area Code 210  
Entity Local Phone Number 918-2000  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Partnership Units Outstanding   107,763,602
Entity Central Index Key 0001110805  
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q2  
Amendment Flag false  
Common Limited Partner [Member]    
Document Information [Line Items]    
Title of 12(b) Security Common units  
Trading Symbol NS  
Security Exchange Name NYSE  
Series A Preferred Limited Partner [Member]    
Document Information [Line Items]    
Title of 12(b) Security Series A Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Units  
Trading Symbol NSprA  
Security Exchange Name NYSE  
Series B Preferred Limited Partner [Member]    
Document Information [Line Items]    
Title of 12(b) Security Series B Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Units  
Trading Symbol NSprB  
Security Exchange Name NYSE  
Series C Preferred Limited Partner [Member]    
Document Information [Line Items]    
Title of 12(b) Security Series C Fixed-to-Floating Rate Cumulative Redeemable Perpetual Preferred Units  
Trading Symbol NSprC  
Security Exchange Name NYSE